Turnover rate of anti-D IgG injected during pregnancy.
Anti-D IgG was injected into 15 Rh-negative women in the 28th week of gestation and into three non-pregnant women. The uptake of anti-D after the intramuscular injections was calculated by measuring the concentration of antibody in the plasma with an autoanalyser. The biological half life and the catabolic rate of anti-D IgG were calculated according to a compartmental model. The recovery in vivo of anti-D was an average 24% in the non-pregnant women and 21% in the pregnant women. The half life of anti-D were 24 and 21 days, respectively. With a dose of 125 micrograms the plasma anti-D concentration was less than 1 ng/ml at about 10 weeks after the injection. With double the dose the concentration at delivery was at least 1 ng/ml. Although 250 micrograms of anti-D IgG seems to be effective when given in the 28th weeks of gestation, the great individual variations in uptake and recovery rates will lead to occasional cases of Rh-immunisation during pregnancy despite all routine regimens.
D000888:Antibodies, Anti-Idiotypic; D005260:Female; D006207:Half-Life; D006801:Humans; D007074:Immunoglobulin G / Q000378:metabolism*; D011247:Pregnancy; D012204:Rh-Hr Blood-Group System
D000888:Antibodies, Anti-Idiotypic; D007074:Immunoglobulin G; D012204:Rh-Hr Blood-Group System